Fusion 360 Sketch Basics

In the video above we look at the Sketch Basics of constraints and dimensions for Fusion 360.

In this example, we are going to sketch up a basic shape, while following a few sketch rules. It’s worthwhile to turn on the origin, as it is important we connect our first sketch entity to it.

Remember, you can only sketch on a face or a plane. Since we don’t have any solids on the screen, when starting with an empty canvas, we will be picking a plane for our first sketch.

When you start your sketch, just create something close enough to your finished geometry. You will use constraints and dimensions to tie everything down afterward.

It is a good rule to start adding constraints before dimensions. Constraints are like rules for the sketches. For this example, we will apply horizontals and perpendicular constraints.

When you are applying your constraints and dimensions, your final goal is to fully define the sketch. This means that the sketch is completely fixed. Fusion 360 indicates this by turning sketch geometry from blue to black.

If you have a hard time figuring out what constraint or dimension you need to apply, you can try to drag a corner with your mouse.

It is very important that you get in the habit of fully constraining your 2D sketches, before extruding them into 3D. If not, someone can easily change the geometry by dragging a corner.